endcap cryostat C installation and feedthroughs
December 2005
Pictures of the LAr endcap cryostat C installation , 2005/12/13
Photos and comments by Thomas Hott:
"i) It is absolutely necessary to remove the 4 pedestals and their
warm cables, i.e. 2 on the left and 2 on the right, because they
would block the access to the jacks and the support lenses where
shims must to be inserted and bolts opened, resp. tightened. ->
Please have a look to the attached photos - I made them to illustrate
how difficult it is to access the necessary point even without
pedestals and cables. On one photo you can see an allen key sticking
in a bolt that is hidden behind a feedthrough. - I had to cut the key
to be able to loosen the bolt at least the minimum bit that is
required to insert the final support shims.
ii) We can't reinstall the pedestals before the Tile Enxtend barrel
is mechanically completed because we have to realign the LAR-EC then
to the correct in height. This requires again access to the back
jacks and support lenses. Unfortunately it can't be done now because
we do not yet know where the Tile EB axis will be in height until the
assembly is completed (don't forget, the aimed alignment precision is
1 mm and the Tile is still deforming until the last module is
inserted representing eventually an ellipse rather than a circle)."
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